Geophysical evidence for breakup volcanism in the Angola and Gabon passive margins

Fernández, Òscar; Oláiz, Antonio; Cascone, Lorenzo; Hernández, Pedro A.; Pereira, A.; Tritlla, J.; Inglés, M.; Aida, B.; Pinto, Irajá Damiani; Rocca, Riccardo; Sanders, Chris O.; Herrá, A.; Tur, Nataliya A.

doi:10.1016/j.marpetgeo.2020.104330

Cited by 22 publications

(21 citation statements)

References 40 publications

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“…Fernandez et al. in recent work (Fernandez et al., 2020) identified breakup volcanism and argue that the Gabon‐Angola margin evolved initially as a magma‐poor margin and in its late stages into a magma‐rich system (Figure 1c). The complex magma‐poor to magma‐rich transition may be explained by rifting of weak crustal and counterflow of depleted lower lithospheric mantle, where the depleted mantle ruptures slightly earlier than final crustal breakup (e.g., model C2, Figures 6 and 11d).…”

Section: Discussionmentioning

confidence: 93%

“…We next compare our model results with four natural systems (Figure 1): the narrow Lofoten‐Vesterålen margin (Faleide et al., 2008), the narrow Newfoundland margin (Sutra et al., 2013), the wide central South Atlantic Kwanza Basin (Clerc et al., 2018; Fernandez et al., 2020), and the wide South Atlantic Orange basin (Blaich et al., 2009; Franke et al., 2010). These margins all have normal thickness oceanic crust in the range of 4–8 km following inception of a mature mid oceanic ridge system and are thus consistent with a normal mantle potential temperature.…”

Section: Discussionmentioning

confidence: 99%

“… Interpreted cross sections for (a) Lofoten‐Vesterålen (Faleide et al., 2008), (b) Newfoundland (Sutra et al., 2013), (c) South Atlantic central segment (Kwanza Basin) (Fernandez et al., 2020), and (d) South Atlantic southern segment (N. Orange Basin) (Blaich et al., 2009) margins. Thickness of early oceanic crust is annotated with a double arrow.…”

Section: Introductionmentioning

confidence: 99%

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Magmatism at Passive Margins: Effects of Depth‐Dependent Wide Rifting and Lithospheric Counterflow

Lü

Huismans

2022

JGR Solid Earth

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Rifted passive margins exhibit a large variety in the timing, distribution, and amount of magmatism. The factors controlling magmatism during rifted margin formation, remain, however, incompletely understood, partly owing to the complex rifting styles. In this study, we use 2‐Dimensional numerical models to investigate the effects of depth‐dependent wide rifting and lithospheric counterflow on magmatism during rifted margin formation. Results show that a strong crust promotes narrow margins with a sharp transition to normal thickness oceanic crust whereas a weak crust promotes depth‐dependent wide rifting, with preferential removal of mantle lithosphere, leading to formation of wide margins with over‐thickened (>18 km) igneous crust in the distal margin. Counterflow of depleted lithospheric mantle, in contrast, may delay syn‐rift magmatism, and result in exhumed a‐magmatic continental mantle at narrow margins. The combination of wide rifting and lithospheric counterflow results in magma‐poor wide margins, with in some cases a transition to excess magmatic activity at breakup. Our models provide an explanation for the contrasting magmatic productivity at narrow and wide rifted margins, such as observed in the Lofoten‐Vesterålen, Newfoundland, Kwanza Basin, and Orange Basin margins.

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Section: Discussionmentioning

confidence: 93%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Magmatism at Passive Margins: Effects of Depth‐Dependent Wide Rifting and Lithospheric Counterflow

Lü

Huismans

2022

JGR Solid Earth

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“…systems has been extensively investigated through excellent 2D and 3D high resolution seismic imagery, combined with borehole datasets (e.g. Fernandez et al, 2020;Mohriak et al, 2012). However, uncertainties related to seismic imaging of salt-related structures limit the understanding of their 3D geometry and kinematics.…”

Section: Instituto Geológico Y Minero De España (Igme)mentioning

confidence: 99%

“…Salt-floored extensional systems associated with salt diapirs and listric faults are common in present-day continental margins such as offshore Angola (e.g. Brun and Fort, 2004;Cramez and Jackson, 2000;Fernandez et al, 2020), Equatorial Guinea (e.g. Tari et al, 2003;Turner, 1999), Brazil (e.g.…”

Section: Introductionmentioning

confidence: 99%

3D reconstruction of syn-tectonic strata in a salt-related orogen: learnings from the Llert syncline (South-central Pyrenees)

Ramos

López‐Mir

Wilson

et al. 2020

GeA

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The Llert syncline is located in the South-central Pyrenees, between the eastern termination of the EW-trending Cotiella Basin and the north-western limb of the NS-trending Turbón-Serrado fold system. The Cotiella Basin is an inverted upper Coniacian-lower Santonian salt-floored post-rift extensional basin developed along the northern Iberian rift system. The Turbón-Serrado fold system consists of upper Santonian – Maastrichtian contractional salt-cored anticlines developed along an inverted transfer zone of the Pyrenean rift system. Based on field research, this paper presents a 3D reconstruction of the Llert syncline in order to further constrain the transition between these oblique salt-related structures. Our results suggest that the evolution of the Llert syncline was mainly controlled by tectonic shortening related to the tectonic inversion of the Cotiella Basin synchronously to the growth of the Turbón-Serrado detachment anticline, and by the pre-compressional structural framework of the Pyrenean rift system. Our contribution provides new insight into the geometric and kinematic relationships of structures developed during the inversion of passive margins involving salt.

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3D crustal-scale structure of the West Iberia margin: a novel approach to integrated structural characterization of passive margins

et al. 2021

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Hyperextended margins are very heterogeneous along the entire length of the margin, so the definition of tectonic domains made exclusively from 2D seismic sections presents serious limitations. In this work we present an approach of the 3D crustal-scale structure of the West Iberia margin (WIM) by modelling eight lithospheric sections, using seismic, wells and gravity data. The continuous nature of gravity data allowed us to propose a new map of tectonic domains within the WIM. Maps of total horizontal (THD) and vertical gradients (dZ) of Bouguer anomaly have been calculated and compared with other criteria such as the crustal structure and thinning factor. This comparative analysis has been carried out on a section proposed as a model for the Western Iberian Margin (Tugend et al. in Tectonics, 2014; Cadenas et al. in Tectonics 37:758-785, 2018), and on four 2 + 1/2D gravimetric models transversal to the margin. The results point out a significant variation in the absolute values of Bouguer anomaly, thinning factor and crustal structure along the margin and, therefore, of the position of the different domain boundaries. Clear patterns that correlating the Bouguer anomaly signal and its derivatives to the tectonic domain are evidenced. Most significantly, the necking-zone and its transition to the hyperextended domain are characterized by high values of the THD of the Bouguer anomaly. The observed patterns in Bouguer anomaly and its derivatives provide a solid constraint for mapping the boundaries between different tectonic domains along the margin, even in those areas where limited deep seismic information could lead to uncertain interpretations. The results of this work can also inform on the general kinematics of the WIM.

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Geophysical evidence for breakup volcanism in the Angola and Gabon passive margins

Cited by 22 publications

References 40 publications

Magmatism at Passive Margins: Effects of Depth‐Dependent Wide Rifting and Lithospheric Counterflow

Magmatism at Passive Margins: Effects of Depth‐Dependent Wide Rifting and Lithospheric Counterflow

3D reconstruction of syn-tectonic strata in a salt-related orogen: learnings from the Llert syncline (South-central Pyrenees)

3D crustal-scale structure of the West Iberia margin: a novel approach to integrated structural characterization of passive margins

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